Characterization and Modeling of SiC LTJFET for Analog Integrated Circuit Simulation and Design

Abstract

The design of analog integrated circuits, for instance, the operational amplifiers, have been widely perfected with devices and processes available in silicon. However, analogous circuits have been the subject of research in Silicon Carbide (SiC). Among SiC devices, 4H-SiC Lateral-Trench JFET (LTJFET) transistor offers advantages and new opportunities to make affordable and reliable analog integrated circuits for harsh environment. In this paper: (1) SiC LTJFET is characterized for modeling and simulation, (2) effect of temperature variation on SiC LTJFET threshold voltage and small signal parameters are reported, (3) gain performance and small signal parameters of the basic analog circuit block, Common Source (CS) amplifier, based on the variation of the load transistors threshold voltage (Vth) are studied and analyzed, and (4) frequency and transient response of the cascoded CS amplifier (CS-Cas) are reported.

The Design of an Operational Amplifier Using Silicon Carbide JFETs

“…(11) (12) As the number of cascoded transistors increases in Fig. 6(d) [14] through 6(f), higher output resistance can be observed.…”

“…This means that moving J2's closer to J1's causes current and transconductance to drop, but a large increase in output resistance results in an increase in the overall gain [12]. It can be realized [12] that in a basic CSA (Fig.…”

“…It can be realized [12] that in a basic CSA (Fig. 5(b)), if the of J1 and J2 are chosen to be 0.5 V and 0.5 V, respectively, a well-balanced combination of gain and drain current can be obtained.…”

“…6(a) to (f). Equations (9) through (12) show the overall output resistance of each configuration with respect to the transconductance and output resistance of the transistors.…”

Vertical Channel Silicon Carbide JFETs Based Operational Amplifiers

“…1) are fabricated [3] in the form of Depletion Mode (DM) with negative threshold voltage (V th ) and Enhancement Mode (EM) with positive V th . Subsequently, they are characterized and modeled [4] from 27°C to 400°C. Both EM and DM devices that are used throughout the design share the same device structure and geometry, with the exception of different Finger Lengths (FLs).…”